Glucocorticoid Receptor Confers Resistance to Antiandrogens by Bypassing Androgen Receptor Blockade

SummaryThe treatment of advanced prostate cancer has been transformed by novel antiandrogen therapies such as enzalutamide. Here, we identify induction of glucocorticoid receptor (GR) expression as a common feature of drug-resistant tumors in a credentialed preclinical model, a finding also confirmed in patient samples. GR substituted for the androgen receptor (AR) to activate a similar but distinguishable set of target genes and was necessary for maintenance of the resistant phenotype. The GR agonist dexamethasone was sufficient to confer enzalutamide resistance, whereas a GR antagonist restored sensitivity. Acute AR inhibition resulted in GR upregulation in a subset of prostate cancer cells due to relief of AR-mediated feedback repression of GR expression. These findings establish a mechanism of escape from AR blockade through expansion of cells primed to drive AR target genes via an alternative nuclear receptor upon drug exposure

Resumption of Immune Checkpoint Inhibitor Therapy After Immune-Mediated Colitis

PURPOSE: Immune checkpoint inhibitor (ICI) therapy often is suspended because of immune-mediated diarrhea and colitis (IMDC). We examined the rate of and risk factors for IMDC recurrence after ICI resumption. METHODS: This retrospective multicenter study examined patients who resumed ICI therapy after improvement of IMDC between January 2010 and November 2018. Univariable and multivariable logistic regression analyses assessed the association of clinical covariates and IMDC recurrence. RESULTS: Of the 167 patients in our analysis, 32 resumed an anti–cytotoxic T-cell lymphocyte-4 (CTLA-4) agent, and 135 an anti–programmed cell death 1 or ligand 1 (PD-1/L1) agent. The median age was 60 years (interquartile range [IQR], 50-69 years). The median duration from IMDC to restart of ICI treatment was 49 days (IQR, 23-136 days). IMDC recurred in 57 patients (34%) overall (44% of those receiving an anti–CTLA-4 and 32% of those receiving an anti–PD-1/L1); 47 of these patients (82%) required immunosuppressive therapy for recurrent IMDC, and all required permanent discontinuation of ICI therapy. The median duration from ICI resumption to IMDC recurrence was 53 days (IQR, 22-138 days). On multivariable logistic regression, patients who received anti–PD-1/L1 therapy at initial IMDC had a higher risk of IMDC recurrence (odds ratio [OR], 3.45; 95% CI, 1.59 to 7.69; P = .002). Risk of IMDC recurrence was higher for patients who required immunosuppression for initial IMDC (OR, 3.22; 95% CI, 1.08 to 9.62; P = .019) or had a longer duration of IMDC symptoms in the initial episode (OR, 1.01; 95% CI, 1.00 to 1.03; P = .031). Risk of IMDC recurrence was lower after resumption of anti–PD-1/L1 therapy than after resumption of anti–CTLA-4 therapy (OR, 0.30; 95% CI, 0.11 to 0.81; P = .019). CONCLUSION: One third of patients who resumed ICI treatment after IMDC experienced recurrent IMDC. Recurrence of IMDC was less frequent after resumption of anti–PD-1/L1 than after resumption of anti–CTLA-

Integrative Molecular Analyses of the MD Anderson Prostate Cancer Patient-derived Xenograft (MDA PCa PDX) Series

PURPOSE: Develop and deploy a robust discovery platform that encompasses heterogeneity, clinical annotation, and molecular characterization and overcomes the limited availability of prostate cancer models. This initiative builds on the rich MD Anderson (MDA) prostate cancer (PCa) patient-derived xenograft (PDX) resource to complement existing publicly available databases by addressing gaps in clinically annotated models reflecting the heterogeneity of potentially lethal and lethal prostate cancer. EXPERIMENTAL DESIGN: We performed whole-genome, targeted, and RNA sequencing in representative samples of the same tumor from 44 PDXs derived from 38 patients linked to donor tumor metadata and corresponding organoids. The cohort includes models derived from different morphologic groups, disease states, and involved organ sites (including circulating tumor cells), as well as paired samples representing heterogeneity or stages before and after therapy. RESULTS: The cohort recapitulates clinically reported alterations in prostate cancer genes, providing a data resource for clinical and molecular interrogation of suitable experimental models. Paired samples displayed conserved molecular alteration profiles, suggesting the relevance of other regulatory mechanisms (e.g., epigenomic) influenced by the microenvironment and/or treatment. Transcriptomically, models were grouped on the basis of morphologic classification. DNA damage response-associated mechanisms emerged as differentially regulated between adenocarcinoma and neuroendocrine prostate cancer in a cross-interrogation of PDX/patient datasets. CONCLUSIONS: We addressed the gap in clinically relevant prostate cancer models through comprehensive molecular characterization of MDA PCa PDXs, providing a discovery platform that integrates with patient data and benchmarked to therapeutically relevant consensus clinical groupings. This unique resource supports robust hypothesis generation and testing from basic, translational, and clinical perspectives

RS3PE Following Treatment With Combination of Hormonal Therapies Plus Ipilimumab in a Patient With Metastatic Prostate Cancer

Introduction: Immune checkpoint inhibitors (ICIs) are often associated with inflammatory toxicities known as immune-related adverse events (irAEs). Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) is an atypical inflammatory arthritis. Herein, we report a case of RS3PE in a patient with metastatic prostate cancer who was receiving a combination of second-generation hormonal therapies plus ipilimumab. Case Presentation: A 59-year-old man with metastatic prostate cancer developed sudden onset of pain and swelling of the right hand after 15 weeks of treatment with second-generation hormonal therapies plus three cycles of ipilimumab. Symptoms alternated to the left hand. Physical examination showed tender, pitting edema of the left hand with tenderness on the right second through fifth metacarpal phalangeal joints, leading to the diagnosis of RS3PE. Ipilimumab was withheld, and the RS3PE self-resolved; however, 1 month later, the patient had another flare of RS3PE. A bone scan showed active inflammation on bilateral wrists and hands. Methotrexate was initiated, and his symptoms resolved over a few days. Methotrexate was discontinued 2 months later, and RS3PE has been in complete remission. His prostate cancer progressed, and radium-223 treatment was initiated. Conclusion: To the best of our knowledge, this is the first reported case of RS3PE after the combined second-generation hormonal therapy plus ipilimumab. Both rheumatologists and oncologists should be aware that RS3PE can develop as an irAE. Understanding the mechanism of ICI therapy–associated RS3PE is critical to identify predictive biomarkers and develop optimal therapeutic strategies that do not sacrifice antitumor immunity

Anti-CTLA-4 Immunotherapy Does Not Deplete FOXP3+ Regulatory T Cells (Tregs) in Human Cancers

PurposeCTLA-4 was the first inhibitory immune checkpoint to be identified. Two mAbs, ipilimumab (IgG1) and tremelimumab (IgG2), which block the function of CTLA-4, have demonstrated durable clinical activity in a subset of patients with advanced solid malignancies by augmenting effector T-cell-mediated immune responses. Studies in mice suggest that anti-CTLA-4 mAbs may also selectively deplete intratumoral FOXP3+ regulatory T cells via an Fc-dependent mechanism. However, it is unclear whether the depletion of FOXP3+ cells occurs in patients with cancer treated with anti-CTLA-4 therapies.Experimental designQuantitative IHC was used to evaluate the densities of intratumoral CD4+, CD8+, and FOXP3+ cells in stage-matched melanoma (n = 19), prostate cancer (n = 17), and bladder cancer (n = 9) samples treated with ipilimumab and in paired melanoma tumors (n = 18) treated with tremelimumab. These findings were corroborated with multiparametric mass cytometry analysis of tumor-infiltrating cells from paired fresh melanoma tumors (n = 5) treated with ipilimumab.ResultsBoth ipilimumab and tremelimumab increase infiltration of intratumoral CD4+ and CD8+ cells without significantly changing or depleting FOXP3+ cells within the tumor microenvironment.ConclusionsAnti-CTLA-4 immunotherapy does not deplete FOXP3+ cells in human tumors, which suggests that their efficacy could be enhanced by modifying the Fc portions of the mAbs to enhance Fc-mediated depletion of intratumoral regulatory T cells.See related commentary by Quezada and Peggs, p. 1130

Cardiometabolic healthcare for men with prostate cancer: an MD Anderson Cancer Center experience

Abstract Background Men diagnosed with prostate cancer are at risk for competing morbidity and mortality due to cardiometabolic disease given their advanced age at diagnosis, high prevalence of pre-existing risk factors, and receipt of systemic therapy that targets the androgen receptor (AR). Expert panels have stressed the importance of cardiometabolic risk assessment in the clinic and proposed evaluating key risks using consensus paradigms. Yet, there is a gap in real-world evidence for implementation of comprehensive cardiometabolic care for men with prostate cancer. Methods This is a retrospective, descriptive study of patients with prostate cancer who were referred and evaluated in the Healthy Heart Program at MD Anderson Cancer Center, which was established to mitigate cardiometabolic risks in men with prostate cancer. Patients were seen by a cardiologist and exercise physiologist to evaluate and manage cardiometabolic risk factors, including blood pressure, cholesterol, blood glucose, tobacco use, and coronary artery disease, concurrent with management of their cancer by a medical oncologist. Results From December 2018 through October 2021, the Healthy Heart Program enrolled 55 men with prostate cancer, out of which 35 had biochemical, locoregional recurrence or distant metastases, while all received at least a single dose of a luteinizing hormone-releasing hormone (LHRH) analog. Ninety-three percent of men were overweight or obese, and 51% had an intermediate or high risk of atherosclerotic cardiovascular disease at 10 years based on the pooled cohort equation. Most men had an overlap of two or more cardiometabolic diseases (84%), and 25% had an overlap of at least 4 cardiometabolic diseases. Although uncontrolled hypertension and hyperlipidemia were common among the cohort (45% and 26%, respectively), only 29% of men followed up with the clinic. Conclusions Men with prostate cancer have a high burden of concurrent cardiometabolic risk factors. At a tertiary cancer center, the Healthy Heart Program was implemented to address this need, yet the utility of the program was limited by poor follow-up possibly due to outside cardiometabolic care and inconvenient appointment logistics, a lack of cardiometabolic labs at the time of visits, and telemedicine visits